While diamond is the choice for strong and sharp tool material in ultra-precision machining, the strong carbon-steel chemical affinity remains a critical problem that results in catastrophic tool wear. Hence, without changing the geometry of these tools, we applied the concept of surface energy modification on the tool surface by implanting a calculated dose of foreign metallic ions to induce minute lattice distortions [1].Together with experimental wettability tests, our density functional theory calculations predicted the reduction in surface energy of diamond doped with gallium ions, which enabled the reduction in diamond tool wear with careful consideration of implantation parameters to avoid amorphization of the diamond. Cutting tool life was extended during turning of ferrous metal resulting from the lower surface energy and corresponding chemical affinity and decreased the coefficient of friction that smoothened the cutting process.

Publications

[1] Y.J. Lee, et al., Micromachining of ferrous metal with an ion implanted diamond cutting tool, Carbon, 152 (2019) 598–608.

Acknowledgements

This research is proudly supported by the Singapore MOE Academic Research Fund Tier 1 Grant (R-265-000-593-114).